Hi Cristián. Firstly, sorry for the troubles you are experiencing.
There is a fix of this problem currently under the integration review MDL-66917, so Moodle should not allow to override the current plugin with an older version any more in the future.
Meanwhile, as Ken says. You will need to replace the folder lib/editor/atto/plugins/recordrtc with the code of the currently installed version 2019052000. You can use the ZIP attached to this post which comes from the default Moodle 3.7+ installation.
Good luck, hope it helps.